How to Choose 12V or 24V? ----IF your car is 12V, pls choose 12V air horn ----IF your car is 24V, pls choose 24V air horn Air Horn Main Features: - Single trumpet, no air system needed.- Easy to fit, glistening chrome finishing and tuned train horn sound.- Suitable for cars, trucks, boats, motorcycle, any 12V /24V vehicles.- Trumpet length: 450mm, trumpets bell width: 95mm.- Attachment screws and brackets included.- Can fit in almost any vehicle, but deliver the big sound you need. Note: the color of the connector screw is random. Specification: Material: Manganese steelPower: 200WSound:150DBFeatures:Portable,DurableColor:SilverSpecial function:Single trumpet air hornProduct weight:1.0010 kgProduct size: 45.00 x 10.00 x 9.50 cm/17.72 x 3.94 x 3.74 inchesAir Horn Package Contents:1 x Single Trumpet Air Horn,1 x Air Compressor1 x Air Hose1 x Bag of Fixings